英文:
Cannot Find and Read Text File on Android Studio (Java)
问题
所以我正在使用Android Studio创建一个移动应用程序，允许用户随机生成角色。我试图逐行读取包含角色姓名的.txt文件，以便能够填充一个ArrayList<String>以保存所有姓名。我尝试过多种方法来读取.txt文件，但始终无法成功，控制台始终声称目录和文件不存在。我尝试过使用BufferedReader、InputStreamReader和Scanner，如下所示：
ArrayList<String> a = new ArrayList<>();
try {
File file = new File(fileName);
InputStream in = new FileInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String curLine = br.readLine();
while (curLine != null){
a.add(curLine);
curLine = br.readLine();
}
} catch (Exception e){
}
还有...
ArrayList<String> a = new ArrayList<>();
try (BufferedReader reader = new BufferedReader(new FileReader(fileName))){
String curLine = reader.readLine();
for (int i = 1; i != lineNum; i++){
a.add(curLine);
curLine = reader.readLine();
}
return curLine;
} catch (Exception e){
}
还有...
ArrayList<String> a = new ArrayList<>();
try {
File myObj = new File(fileName);
System.out.println(myObj.getAbsolutePath());
Scanner myReader = new Scanner(myObj);
while (myReader.hasNextLine()) {
a.add(myReader.nextLine());
}
myReader.close();
} catch (Exception e) {
}
虽然所有这些方法都失败了。我尝试使用file.getAbsolutePath()来显示绝对路径，路径是正确的。我尝试将文件放置在与src文件夹平行的位置，与src文件夹平行的文件夹中，res文件夹中等等。此外，值得注意的是，我通过调用我的FileIO类中的静态方法来运行这些代码，其中我将String fileName作为参数传递进去。我是否漏掉了什么？当我在NetBeans或Eclipse中执行此操作时，从文本文件中读取没有问题，实际上，NetBeans中的一些旧项目已经成为我在Android Studio尝试时的模板。
这是我在Android Studio中的第一个项目，所以我很可能做错了一些事情，所以非常感谢任何帮助！
注：我知道我在提供的代码中捕获异常的方式不高效，但当我尝试使用FileNotFoundException捕获异常时，Android Studio中的调试器因某种奇怪的原因无法正常工作。
英文:
So I am creating a mobile application using Android Studio that allows the user to randomize and generate a character. I am trying to read a .txt file of the characters' names, line by line, so that I can populate an ArrayList<String> that will hold all the names. Everything I have tried in an attempt to read the .txt file has not worked and the console always claims that the directory and file doesn't exist. I have tried using a BufferedReader, InputStreamReader, and Scanner in many ways, as shown below:
ArrayList<String> a = new ArrayList<>();
try {
File file = new File(fileName);
InputStream in = new FileInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String curLine = br.readLine();
while (curLine != null){
a.add(curLine);
curLine = br.readLine();
}
}
catch (Exception e){
}
and...
ArrayList<String> a = new ArrayList<>();
try (
BufferedReader reader = new BufferedReader(new FileReader(fileName));
){
String curLine = reader.readLine();
for (int i = 1; i != lineNum; i++){
a.add(curLine);
curLine = reader.readLine();
}
return curLine;
}
catch (Exception e){
}
and...
ArrayList<String> a = new ArrayList<>();
try {
File myObj = new File(fileName);
System.out.println(myObj.getAbsolutePath());
Scanner myReader = new Scanner(myObj);
while (myReader.hasNextLine()) {
a.add(myReader.nextLine());
}
myReader.close();
} catch (Exception e) {
}
though all of them fail to work. I have tried showing the absolute path using file.getAbsolutePath() and the path is correct. I have tried putting the file parallel to the src folder, in a folder that is parallel with the src folder, in the res folder, and more. In addition, it may be important to note that I am running these lines by calling a static method in my FileIO class where I am passing in the String fileName as an argument. Is there something I'm missing? When I do this in NetBeans or Eclipse I have no issue with reading from a text file, in fact some of my old projects in NetBeans have been a template for me when I'm attempting this in Android Studio.
This is my first project with Android Studio so I am most likely doing something incorrect, so any help would be appreciated!
Note: I know that my convention for catching Exceptions is not efficient in the code provided, though when I try to catch the Exception with a FileNotFoundException, the debugger in Android Studio fails to work for some odd reason.
答案1
得分: 0
请尝试以下代码：
ArrayList<String> a = new ArrayList<>();
File file = new File(filename);
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
a.add(line);
}
br.close();
} catch (IOException e) {
// 在此记录错误并提供给我们
}
确保你的“filename”不是一个目录。
通过记录一些断言的结果来测试你的文件：
System.out.println("文件是否存在？" + file.exists());
System.out.println("文件是目录？" + file.isDirectory());
System.out.println("文件可读？" + file.canRead());
并将结果反馈给我们。
英文:
Can you try this :
ArrayList<String> a = new ArrayList<>();
File file = new File(filename);
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
a.add(myReader.nextLine());
}
br.close();
}
catch (IOException e) { // OR CATCH AT LEAST EXCEPTION IF IT DOESNT WORK FOR FILEIOEXCEPTION
// HERE LOG YOUR ERROR AND GIVE IT TO US
}
Ensure that your "filename" is not a directory.
Test your file by logging results of some assertions:
System.out.println("file exists? " + file.exists());
System.out.println("file is Dir? " + file.isDirectory());
System.out.println("file can be read? " + file.canRead());
and give us the results.
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